In an NFC (Near Field Communication) module or a wireless power supply module, a resonance frequency may fluctuate because of variability of electrical characteristic of a coil used for an antenna or usage circumstance of the modules. In order to adjust the resonance frequency, a variable capacitance device of which capacitance changes according to a bias voltage is used. For example, there is known a variable capacitance device in which a plurality of capacitors of which capacitance changes according to an applied voltage are coupled between signal terminals in series and are coupled in parallel between bias terminals (see Japanese Patent Application Publication No. 2005-508096). And, there is disclosed a capacitance change ratio can be largely changed by adjusting a resistance of a plurality of resistances coupled between a capacitor and a bias terminal in such a variable capacitance device (see Japanese Patent Application Publication No. 2014-103181).
There is known a resistance heater having a resistance heater provided in ladder shape between electrodes for the purpose of uniform heating (see Japanese Patent Application Publication No. H7-192857). There is known a resistor having a first ladder resistance path in parallel with a main resistance path and a second ladder resistance path vertical to the main resistance path and can adjust a resistance thereof with high accuracy (see Japanese Patent Application Publication No. H9-306703).